springboot打成jar后获取classpath下文件
代码如下:
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ClassPathResource resource = new ClassPathResource( "app.keystore" );
File file = resource.getFile();
FileUtils.readLines(file).forEach(System.out::println);
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解决方式如下:
1. Spring framework
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String data = "" ;
ClassPathResource cpr = new ClassPathResource( "static/file.txt" );
try {
byte [] bdata = FileCopyUtils.copyToByteArray(cpr.getInputStream());
data = new String(bdata, StandardCharsets.UTF_8);
} catch (IOException e) {
LOG.warn( "IOException" , e);
}
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2.use a file
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ClassPathResource classPathResource = new ClassPathResource( "static/something.txt" );
InputStream inputStream = classPathResource.getInputStream();
File somethingFile = File.createTempFile( "test" , ".txt" );
try {
FileUtils.copyInputStreamToFile(inputStream, somethingFile);
} finally {
IOUtils.closeQuietly(inputStream);
}
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Resource resource = new ClassPathResource( "data.sql" );
BufferedReader reader = new BufferedReader( new InputStreamReader(resource.getInputStream()));
reader.lines().forEach(System.out::println);
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String content = new ClassPathResourceReader( "data.sql" ).getContent();
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@Value ( "${resourceLoader.file.location}" )
@Setter
private String location;
private final ResourceLoader resourceLoader;
public void readallfilesfromresources() {
Resource[] resources;
try {
resources = ResourcePatternUtils.getResourcePatternResolver(resourceLoader).getResources( "classpath:" + location + "/*.json" );
for ( int i = 0 ; i < resources.length; i++) {
try {
InputStream is = resources[i].getInputStream();
byte [] encoded = IOUtils.toByteArray(is);
String content = new String(encoded, Charset.forName( "UTF-8" ));
}
}
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
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springboot-项目获取resources下文件碰到的问题(classPath下找不到文件和文件名乱码)
项目是spring-boot + spring-cloud 并使用maven 管理依赖。在springboot+maven项目下怎么读取resources下的文件实现文件下载?
怎么获取resources目录下的文件?(相对路径)
方法一:
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File sourceFile = ResourceUtils.getFile( "classpath:templateFile/test.xlsx" ); //这种方法在linux下无法工作
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方法二:
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Resource resource = new ClassPathResource( "templateFile/test.xlsx" ); File sourceFile = resource.getFile();
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我使用的是第二种。
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@PostMapping ( "/downloadTemplateFile" )
public JSONData downloadTemplateFile(HttpServletResponse response) {
String filePath = "templateFile/test.xlsx" ;
Resource resource = new ClassPathResource(filePath); //用来读取resources下的文件
InputStream is = null ;
BufferedInputStream bis = null ;
OutputStream os = null ;
try {
File file = resource.getFile();
if (!file.exists()) {
return new JSONData( false , "模板文件不存在" );
}
is = new FileInputStream(file);
os = response.getOutputStream();
bis = new BufferedInputStream(is);
//设置响应头信息
response.setCharacterEncoding( "UTF-8" );
this .response.setContentType( "application/octet-stream; charset=UTF-8" );
StringBuffer contentDisposition = new StringBuffer( "attachment; filename=\"" );
String fileName = new String(file.getName().getBytes(), "utf-8" );
contentDisposition.append(fileName).append( "\"" );
this .response.setHeader( "Content-disposition" , contentDisposition.toString());
//边读边写
byte [] buffer = new byte [ 500 ];
int i;
while ((i = bis.read(buffer)) != - 1 ) {
os.write(buffer, 0 , i);
}
os.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
return new JSONData( false , "模板文件不存在" );
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (os != null ) os.close();
if (bis != null ) bis.close();
if (is != null ) is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return new JSONData( "模板文件下载成功" );
}
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高高兴兴的启动项目后发现还是找不到文件,错误日志:
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java.io.FileNotFoundException: class path resource [templateFile/test.xlsx] cannot be resolved to URL because it does not exist
at org.springframework.core.io.ClassPathResource.getURL(ClassPathResource.java: 195 )
at org.springframework.core.io.AbstractFileResolvingResource.getFile(AbstractFileResolvingResource.java: 129 )
at com.citycloud.parking.support.controller.operate.OperateBusinessUserController.downloadTemplateFile(OperateBusinessUserController.java: 215 )
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java: 62 )
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java: 43 )
at java.lang.reflect.Method.invoke(Method.java: 498 )
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java: 209 )
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java: 136 )
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java: 102 )
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java: 877 )
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java: 783 )
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java: 87 )
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java: 991 )
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java: 925 )
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java: 974 )
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java: 877 )
at javax.servlet.http.HttpServlet.service(HttpServlet.java: 661 )
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java: 851 )
at javax.servlet.http.HttpServlet.service(HttpServlet.java: 742 )
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java: 231 )
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java: 166 )
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java: 52 )
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java: 193 )
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java: 166 )
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java: 158 )
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java: 126 )
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java: 111 )
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java: 107 )
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java: 193 )
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因为我知道Resource resource = new ClassPathResource("templateFile/test.xlsx");就是到classPath*(注意这里有个*)下去找,然后就去项目本地的目录下找classPath下是否有这个文件(maven的classPath在 “target\classes”目录下),就发现并没有这个文件在。
后面仔细想想这是Maven项目啊,所以就找pom.xml文件去看看,突然想起:springboot的maven默认只会加载classPath同级目录下文件(配置那些),其他的需要配置<resources>标签:
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< build >
< resources >
< resource >
< directory >src/main/java</ directory >
< includes >
< include >**/*.properties</ include >
< include >**/*.xml</ include >
</ includes >
<!--是否替换资源中的属性-->
< filtering >false</ filtering >
</ resource >
< resource >
< directory >src/main/resources</ directory >
< includes >
< include >**/*.properties</ include >
< include >**/*.xml</ include >
< include >**/*.yml</ include >
< include >**/Dockerfile</ include >
< include >**/*.xlsx</ include >
</ includes >
<!--是否替换资源中的属性-->
< filtering >false</ filtering >
</ resource >
</ resources >
</ build >
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重新启动,再到classPath下看,发现有了这个文件了,同时也能获取了。如果文件名为中文的话就会出现乱码的情况。
怎么解决文件名中文乱码?
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Access-Control-Allow-Origin →*
Access-Control-Allow-Credentials → true
Access-Control-Allow-Headers →accessToken,Access-Control-Allow-Origin,Content-Type,X-Requested-With,accept,Origin,Access-Control-Request-Method,Access-Control-Request-Headers
Access-Control-Allow-Methods →POST,GET,PUT,PATCH,DELETE,OPTIONS,HEAD
Access-Control-Max-Age → 360
Content-disposition →attachment; filename= "????????-??????????.xlsx"
Content-Type →application/octet-stream;charset=UTF- 8
Transfer-Encoding →chunked
Date →Fri, 19 Apr 2019 06 : 47 : 34 GMT
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上面是使用postman测试中文乱码response响应头相关信息。
后面怎么改都乱码,然后我就试着到浏览器中请求试试,结果发现只是postman的原因,只要文件名编码跟返回内容编码一致("Content-disposition"和“ContentType”)就行:
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this .response.setContentType( "application/octet-stream; charset=iso-8859-1" );
StringBuffer contentDisposition = new StringBuffer( "attachment; filename=\"" );
String fileName = file.getName();
contentDisposition.append(fileName).append( "\"" );
//设置文件名编码
String contentDispositionStr = new String(contentDisposition.toString().getBytes(), "iso-8859-1" );
this .response.setHeader( "Content-disposition" , contentDispositionStr);
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到此全部结束!
以上为个人经验,希望能给大家一个参考,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/qq_27384769/article/details/99877083